/* observer.vala
 *
 * Copyright (C) 2008  Frederik 'playya' Sdun
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Author:
 *     Frederik 'playya' Sdun <Frederik.Sdun@gmail.com>
 */
using GLib;

namespace Rob{
    public interface IObserver: GLib.Object
    {
        public abstract void update( Rob.Observable o );
    }


    public class Observable : GLib.Object
    {
        protected List<Rob.IObserver> _observers;
        protected bool _fulfilled;
        public virtual bool fulfilled
        {
            get{ return this._fulfilled; }
            set
            {
                if( value != _fulfilled)
                {
                    _fulfilled= value;
                    send_notify();
                }    
            }
        }

        public virtual void addObserver(Rob.IObserver o)
        {
            _observers.prepend(o);
        }

        public virtual void rmObserver(IObserver o)
        {
            _observers.remove(o);
        }
        //notify is used by gobject
        public virtual void send_notify()
        {
            foreach( var o in _observers )
            {
                o.update( this );
            }
        }
        construct 
        {
            _observers = new List<Rob.IObserver>();
            _fulfilled = false;
        }
    }
}
